Armor piercing bullet

ABSTRACT

An armor piercing bullet is made by first forcing a hard metal core into a sleeve-shaped filler and embedding the core therein. Thereafter the filler and the core are forced, as one unit, into a soft metal bullet jacket. In this way a very good centering of the core within the bullet is obtained, which is necessary for stabilising the bullet in its trajectory. Furthermore, the forces exerted on a quantity of incendiary material which may be located in the jacket&#39;&#39;s tip are limited in this way so that the risk of spontaneous combustion of this material is decreased.

liite ttes atent 1 [111 3,782,287

Sie Jan. 1, 1974 [54] ARMOR PIERCING BULLET 3,208,385 9/1965 Perniss 10252 l,l79, 86 419 6 V K [75] Inventor: Liep Swan Sie, Brandarls, 6 l 1 anampen 02/52 Netherlands Primary Examiner-Benjamin A. Borchelt [73]Assignee: Staatsbedrijf Artillerie lnrichtingen, Assistant ExaminerJ. V.Doramus Hembrug-Zaandam, Netherlands Attorney-John P. Snyder [22] Filed:Oct. 26, 1971 [57] ABSTRACT [21] Appl' l92001 An armor piercing bulletis made by first forcing a hard metal core into a sleeve-shaped fillerand embed- [30] Foreign Application Priority Data ding the core therein.Thereafter the filler and the Oct. 28, 1970 Netherlands 7015837 core areforced, as one u nt a s ft m tal bullet jacket. In this way a very goodcentering of the core [52] US. Cl. 102/52 within the bullet is Obtained,which is n ry r [51] Int. Cl. F42b 11/14, F42b 13/04 stabilising thebullet in its trajectory. Furtherm the [58] Field of Search 102/52, 66,67 orces exerted on a quantity of incendiary material which may belocated in the jackets tip are limited in [56] R f en Cit d this way sothat the risk of spontaneous combustion of this material is decreased.

91 1,591 2/1909 Hoxie lO2/52 2 Claims, 6 Drawing Figures ARMOR PIERCINGBULLET The present invention relates to a method of making an armorpiercing bullet having a core of hard material, adapted to pierce armorplate, which is embedded in a filler inside a jacket of substantiallysoft metal.

Bullets of the kind specified can consist of a jacket of tombac(approximately 90% Cu. and approximately Zn), in which a hard metal coreis embedded in a lead filler. In the assembly of a bullet of the kindspecified frequently the cavity inside the bullet jacket is first filledwith lead, whereafter the core is forced into the lead filler, the corehaving if necessary at its front a penetration element which preventsthe core from ricocheting off armor plate if it hits it at an unsuitableangle.

The lead is forced around the core and then fills the space between thecore and the jacket. Sometimes the cavity inside the bullet jacketbehind the core thus embedded is closed by an extra amount of lead. Whena bullet is assembled in this way it is difficult to centre the hardmetal core satisfactorily inside the bullet jacket. Moreover,satisfactory centring is important to stabilise the bulletsatisfactorily in its trajectory. If the bullet is also to contain infront of the core a quantity of incendiary material which is introduced,for instance, before the lead is introduced into the cavity in thejacket, there is also the risk that the forcing of the core into thelead will exert excessive pressure on the incendiary material, resultingin the spontaneous combustion or explosion thereof.

It is an object of the invention to provide a novel method of assemblingbullets of the kind specified by means of which the centering of thecore inside the bullet jacket, important for ballistic reasons, isfacilitated and which limits the forces exerted by the introduction ofthe core on any incendiary material disposed at the tip of the bulletjacket.

To that aim the invention provides a novel method of making an armorpiercing bullet, which comprises the steps of:

a. forming a jacket 1 having a cylindrical body portion 101 ofsubstantially uniform internal diameter surmounted by a tapered tipportion 102 joined to and closing one end 103 of said body portion 101,the op posite end 104 of said body portion 101 being open;

b. forming an armor piercing core 3 having an outer diameter less thansaid inner diameter of said jacket 1;

c. forming a filler 2 having at least a sleevelike portion 201 ofsubstantially uniform wall thickness defining an interior space 202 ofsubstantially the same diameter as said outer diameter of said core 3and an outer surface 203 of substantially the same diameter as saidinternal diameter of said jacket 1;

d. inserting said core.3 within said sleevelike portion 201 of thefiller; and

e. inserting the core 3 and surrounding filler 2 of step ((1) into theopen end 104 of said jacket 1 whereby to center said core 3 within saidjacket 1.

In a method of this kind the core is first embedded in a substantiallybush-shaped filler and then forced together with the bush-shaped filleras a unit into the jacket. The advantage of a method of the kindspecified is that the core is embedded in the filler outside the bulletjacket, thus enabling the embedding to be more accurately controlled.The shape and composition of the filler also be such as to afford aballistically desirable distribution of the mass of the resultantcombination of the bush-shaped filler and the core, and also a simplerand more satisfactorily reproducible manner of introducing this massinto the bullet jacket.

Conveniently according to the invention, on the rear sideof the core thebush-shaped filler merges into a solid portion of round cross-sectionwhich closes the cavity of the bullet jacket at or adjacent its rearend. The result is that the core and filler can be satisfactorilyhandled as a whole while rendering superfluous the introduction of aseparate element closing the cavity inside the bullet jacket at oradjacent its rear end.

If, as is usually the case, the core is of a conical or substantiallyconical shape at its front end, according to the invention before thebush-shaped filler is forced together with the core into the bulletjacket, the bushshaped filler is shrunk around a portion of the cone ofthe core at the front end of its cylindrical portion. As a result ofthis step the core is protected against axial displacement in relationto the bush-shaped filler, any such displacement during the firing ofthe bullet being undesirable for ballistic reasons.

If, as is often the case, the cavity inside the bullet narrows in theforward direction, conveniently according to the invention at its frontend the diameter of the bush-shaped filler changes abruptly, and theshoulder formed in the generated surface of the bush-shaped filler bythe change in diameter is used as a stop to locate the filler and thecore embedded therein in the bullet jacket. This step gives extraprotection to the bush-shaped filler and the core in the bullet jacket.

The method according to the invention produces a bullet whose ballisticproperties are satisfactorily reproducible. In comparison with a bulletof the same calibre, in which the core bears directly against the insidesurface of the bullet jacket and therefore has a larger diameter, thebullet according to the invention has the further advantage of enablinga core of heavier material to be used, maintaining the same overallweight and other ballistic properties, and resulting in a greater depthof penetration.

The invention will be more clearly understood from the followingdescription with reference to the accom' panying drawings, wherein:

FIG. 1 is an axial section through a bullet according to the inventionand FIGS. 2 to 6 are diagrammatic axial sections showing a number ofsuccessive phases in the production of the bullet as illustrated in FIG.1.

In its finished state, as illustrated in FIG. 1, the bullet consists ofa jacket ll of tombac (approximately Cu and approximately 10% Zn)containing a substantially bush-shaped filler 2 of aluminium havingembedded therein a core 3 of hard metal having a hardness of, forinstance, 61 on the Rockwell C scale. At the front portion 102 thecavity 4 in the jacket 1 can be filled with an incendiary material 5. Atthe rear side the cavity 4 is closed off by a solid portion 6 of thefiller 2, where the rear end 7 of the jacket 1 is folded round.Similarly, the front end 8 of the tiller 2 is folded around a portion301 of the conical tip 302 of the core 3. Adjacent the front end 8 thecylindrical sleeve portion 201 of the filler 2 also changes its outsidediameter abruptly (clearly visible in FIGS. 2 and 3). The resultantshoulder 9 bears as a stop against the inside of the bullet jacket 1 andlocates the filler 2 therin. Similarly, the core 3 is located in thefiller 2 by the front end 8 thereof so that the core is protected fromdisplacement in relation to the filler 2 and the jacket 1. Since thefiller is of aluminium, a core material of considerable specific weightcan be used without exceeding the weight limits customary for a bulletof this calibre, something which would be undesirable for ballisticreasons.

FIGS. 2 to 6 illustrate diagrammatically a number of phases of themaking of the bullet, FIGS. 2 and 3 showing the introduction of the core3 into the filler 2, while FIGS. 4 to 6 illustrate how the filler withthe core embedded therin is forced into the jacket 1.

As can be seen from FIG. 2, an aluminum bush 2 produced, for instance,by impact intrusion and acting as a filler is placed in the cavity 11 ofa die 12 having at its bottom an ejection pin 10.

The bush or filler has a sleevelike portion 201 of substantially uniformwall thickness, defining an interior space 202 of substantially the samediameter as the outer diameter of the core 3. The outer surface 203 ofthe bush 2 has substantially the same diameter as the internal diameterof the jacket 1. Top end 8 of the bush 2 is of smaller diameter thansleevelike portion 201, however, so that the filler has acircumferential shoulder 9.(see FIG. 2) between top end 8 and sleevelikeportion 201.

A core 3 is then forced by, for instance, a punch 13 into the cavity 202of the bush 2, the core 3 being guided in a bore 14 in a guide member.

FIG. 3 shows how the top end 8 sleevelike portion 201 of the bush isfolded by a folding punch 16 around a portion 301 of the conical tip 302of the core 3 so that the core is satisfactorily embedded in the filler2 (c.f., for instance, also FIG. 4). As a result the core 2 is locked inthe longitudinal direction between the top of front end 8 and a solidrear end portion 6 of the filler 2.

FIGS. 4, and 6 show how the core 3 embedded in the filler 2 is forcedinto the bullet jacket 1.

The bullet jacket is formed as having a cylindrical body portion 101 ofsubstantially uniform internal diameter surmounted by a tapered tipportion 102 joined to and closing one end 103 of the body portion 101,the latter one being open at its opposite end 7.

The jacket 1 is now placed in a cavity 19 of a die 20 having at itsbottom an ejection pin 18, whereafter a quantity of incendiary material5 is introduced into the tip portion 102.

FIG. 4 shows how the filler 2, together with the core 3 embeddedtherein, is forced by a press punch 17 into the cavity 4 until theshoulder 9 of the filler 2 comes into abutment against the inside of thetapered tip portion 102 of the jacket (see FIG. 5). FIG. 5 shows thatthe rear part of the cylindrical body portion 101 of the jacket 1 isthen forced by a punch 21 around the solid rear portion 6 of the filler2. Finally (c.f. FIG. 6) open rear end 7 of the jacket, projectingoutside solid rear portion 6 of the filler 2, is folded by a foldingtool 22 around the rear portion of the filler. No separate parts have tobe used for closing the rear end of the bullet which then has the shapeaccording to FIG. 1.

The operation of the tool parts 10, 12, 13, 15, 16, 17, 18, 20, 21 and22 does not form part of the invention and is therefore not discussed inany detail.

I claim:

1. An armor piercing bullet comprising an external jacket having adiameter and length conforming to a selected ordnance caliber,

an armor piercing core located within said jacket,

and a filler snugly fitted within said jacket and locating said coretherewithin, said jacket, filler and core cumulatively providing apredetermined bullet weight which is dictated by said selected ordnancecaliber;

said jacket being of shell-like form receiving said filler and saidcore, said jacket including an elongated body portion of uniformexternal and internal diameter and a tapered tip portion surmountingsaid body portion to present an internal cavity surface tapering fromsaid uniform internal diameter of the body portion and closing saidjacket at its forward end;

said jacket being of integral one piece construction,

said core being of higher specific weight than the jacket and thefiller, the jacket and the filler being of soft material relative tosaid core;

said filler including an elongated shell-like portion snugly received insaid elongated body portion of the jacket and presenting a bore coaxialwith said jacket and opening into said internal cavity of the jacket;and

said core including an elongated cylindrical body portion snuglyreceived in said bore in coaxial relation within said jacket and a tipportion projecting from said bore, said core being of a specific weightand hardness sufficiently high as both to render it armor piercing andto limit its dimensions in achieving said predetermined bullet weightsuch that said tip portion of the core projects into said internalcavity of the jacket with clearance whereby said filler constitutes thesole locating and centering means for the core.

2. An armor piercing bullet as defined in claim 1 wherein said filler isprovided with a solid rear end portion closing the rear end of saidjacket.

1. An armor piercing bullet comprising an external jacket having adiameter and length conforming to a selected ordnance caliber, an armorpiercing core located within said jacket, and a filler snugly fittedwithin said jacket and locating said core therewithin, said jacket,filler and core cumulatively providing a predetermined bullet weightwhich is dictated by said selected ordnance caliber; said jacket beingof shell-like form receiving said filler and said core, said jacketincluding an elongated body portion of uniform external and internaldiameter and a tapered tip portion surmounting said body portion topresent an internal cavity surface tapering from said uniform internaldiameter of the body portion and closing said jacket at its forward end;said jacket being of integral one piece construction, said core being ofhigher specific weight than the jacket and the filler, the jacket andthe filler being of soft material relative to said core; said fillerincluding an elongated shell-like portion snugly received in saidelongated body portion of the jacket and presenting a bore coaxial withsaid jacket and opening into said internal cavity of the jacket; andsaid core including an elongated cylindrical body portion snuglyreceived in said bore in coaxial relation within said jacket and a tipportion projecting from said bore, said core being of a specific weightand hardness sufficiently high as both to render it armor piercing andto limit its dimensions in achieving said predetermined bullet weightsuch that said tip portion of the core projects into said internalcavity of the jacket with clearance whereby said filler constitutes thesole locating and centering means for the core.
 2. An armor piercingbullet as defined in claim 1 wherein said filler is provided with asolid rear end portion closing the rear end of said jacket.